Systems biology of the cell

Question 1

What metaphor is used in the painting “La Clairvoyance”?

Answer 1

Seeing beyond the visible to predict cell dynamics

Question 2

What are four key things cells must do?

Answer 2

Divide move or stay put differentiate and function properly

Question 3

What enables cells to divide move differentiate and function?

Answer 3

Communication adhesion and polarity

Question 4

What organism demonstrates auto organisation?

Answer 4

Hydra

Question 5

What is self organisation?

Answer 5

Cells organising into structures without instructions

Question 6

What hypothesis explains how cells sort?

Answer 6

Differential Adhesion Hypothesis

Question 7

What does the Differential Adhesion Hypothesis state?

Answer 7

Cells adhere with different strengths and sort like oil and water

Question 8

How was cell surface tension experimentally demonstrated?

Answer 8

Foty et al 1996 squeezed cell aggregates

Question 9

What is the Cellular Potts Model?

Answer 9

A simulation model of cells based on surface mechanics and adhesion

Question 10

What three energy components are used in CPM modelling?

Answer 10

Pressure from volume change cortical tension and adhesion energy

Question 11

What is the equation for total cell energy?

Answer 11

E p a equals Jp plus lambda p p minus P squared plus lambda a a minus A squared

Question 12

What does the CPM show when cells are alone?

Answer 12

They become round

Question 13

What happens when cells are in contact in CPM?

Answer 13

They form a honeycomb hexagonal lattice

Question 14

What is emergent behaviour in tissue modelling?

Answer 14

Collective cell organisation from simple adhesion rules

Question 15

What molecule mediates cell adhesion?

Answer 15

Cadherins

Question 16

What stabilises E cadherin interactions?

Answer 16

A two tiered mechanism

Question 17

What is the first take home message?

Answer 17

Simple adhesion differences can lead to self organisation

Question 18

What was Sachs’ contribution to plant biology?

Answer 18

Described an ideal dicot body plan

Question 19

What’s unique about plant cell neighbours?

Answer 19

They do not change neighbours

Question 20

What influences plant morphology?

Answer 20

Gene networks environment soil and ecology

Question 21

How is plant tissue organised?

Answer 21

Through internal signal flows

Question 22

How do plants respond to stimuli?

Answer 22

With chemical signals like auxin

Question 23

What drives polar auxin transport?

Answer 23

Polarised membrane transporters

Question 24

What does polar auxin transport create?

Answer 24

Stable gradients that instruct growth

Question 25

Is auxin transport alone sufficient for patterning?

Answer 25

Yes shown by mathematical models

Question 26

What do auxin gradients do?

Answer 26

Guide root patterning even during growth

Question 27

What animal analogy helps understand plant roots?

Answer 27

Comparison to intestinal villi

Question 28

What does patterned auxin transport ensure?

Answer 28

Stability of development zones and uptake regions

Question 29

What is a keratocyte?

Answer 29

A motile cell showing movement and shape change

Question 30

What makes up the actin cytoskeleton?

Answer 30

G actin F actin Arp2 3 complex

Question 31

What do small G proteins do?

Answer 31

Control polarity and motility

Question 32

Which G proteins are involved in cell dynamics?

Answer 32

Rac Rho Cdc42

Question 33

Where are Rac and Cdc42 active?

Answer 33

At the front of the cell

Question 34

Where is Rho active?

Answer 34

At the rear of the cell

Question 35

What system controls G protein cycling?

Answer 35

GEFs and reaction diffusion dynamics

Question 36

Why does reaction diffusion create spatial patterns?

Answer 36

Due to fast cytosol and slow membrane diffusion

Question 37

What can full cell models simulate?

Answer 37

Shape movement conflict and responsiveness

Question 38

What can go wrong in full cell models?

Answer 38

Cells deform when hitting a wall

Question 39

How do groups of cells behave differently?

Answer 39

Crowding causes coordinated movement

Question 40

What drives collective movement in crowded cells?

Answer 40

Spatial constraints not signalling